Such retaining devices are known in a wide range of different variants and examples of embodiments. For instance, DE 10 2008 019 766 B1 discloses such a device, wherein, in the vicinity of the gripping opening, the gripping arms are held in the closed position by means of a tension spring.
A retaining device of the generic type is disclosed in the utility model DE 297 13 510 U1, in which, in one variant embodiment, parts of the gripping arms which extend beyond the axis of rotation are acted upon by a compression spring in order to apply the closing force.
The known solutions already exhibit some advantages, and therefore the object of the invention is to further develop such a device so that not only are the closing forces optimally applied but also the gripping arms are subjected to a force for centring purposes.
With a device of the type described above, this object is achieved according to the invention in that the gripping arms have extensions on the other side of the respective pivot axle, said extensions having rod- or rail-shaped receptacles, in particular cylindrical receptacles, for guiding at least one compression spring and for applying a bending force to the compression spring or to sub-segments of the compression spring.
By passing a plurality of turns of a compression spring through the receptacles according to the invention, an additional adjusting pressure is exerted on the respective gripping arm when the central axes of the cylindrical receptacles assume a certain angular offset from each other, since these receptacles which serve as spring pins can also transmit bending moments and thus are able to bend the compression spring axis and/or to absorb the forces thereof by springing back.